逆断层活化诱发冲击地压的危险性研究

采用FLAC3.03D数值模拟软件,以接触面单元模拟断层上下盘构造关系,模拟在逆断层地质构造下,工作面从断层下盘向断层面推进过程中,矿山压力分布规律以及断层带位移变化规律。结果表明,在逆断层地质构造下,工作面从下盘向断层推进过程中,距断层面距离不断减小,断层滑移量随工作面的推进逐渐增大;逆断层面上应力变化受采动影响活化范围在断层面前方40 m处,剪切应力与法向应力随工作面的推进逐渐增大,剪切应力变化高于法向应力,诱发冲击危险性增大。     

不同断层落差采动应力及活化规律优化研究

以兴隆庄煤矿为工程背景,采用FLAC~(3D)数值模拟,研究了不同断层落差条件下工作面推进时的采动应力及活化规律。研究表明:下盘工作面开采时,顶底板围岩应力集中程度和工作面前方支承压力随着落差的增大而增加,而上盘工作面开采时则表现出相反的规律。下盘工作面开采,对于低位岩层,当工作面距断层30 m时,剪切应力与法向应力比值最大,此时,断层易活化、失稳。当断层落差为8 m时,剪切应力与法向应力比值最大;当断层落差为4 m时,比值最小。对于高位岩层,剪切应力与法向应力比值的最大值随断层落差增大而增加;上盘工作面开采,剪切应力与法向应力比值变化趋势与断层落差变化基本保持一致。上、下盘工作面开采,随着断层落差的增大,顶板下沉量逐渐增加。     

不同开挖引起断层活化的数值模拟对比分析

强度较低的断层面,周围采动活动易于诱导其断层活化,引发冲击地压。经验表明,在不同采动方案下,引起断层活化的程度存在差异。利用UDEC数值模拟软件,分别模拟工作面从逆断层的上盘和下盘逼近断层回采过程,对比研究断层面最大剪切应力和对应法向应力的演化规律以及断层面上、下盘相对运动规律。结果显示:在工作面回采过程中,工作面距断层水平距离越近,越易于诱导断层活化;工作面在逆断层上盘逼近时,断层相对稳定,活化程度较低;工作面在逆断层下盘推进时,断层活化程度较大,诱发冲击地压的危险性很大。研究表明巷道在逆断层上盘开挖比在下盘更安全、稳定。     

正断层上盘边角煤开采诱发断层活化规律

为研究边角煤工作面采动断层活化规律,基于兴隆庄煤矿肖家庄三号正断层上盘5313工作面遗留边角煤开采,采用数值模拟研究工作面采动不同层位断层面应力和断层滑移量演化规律,分析采动诱发断层活化失稳的可能性。研究结果表明:随工作面与断层距离减小,断层面剪切应力与法向应力增大,两者比值升高,同时断层滑移量随之增长,断层活化失稳可能性增大;当工作面距断层小于30 m时,断层面应力比值显著升高,滑移量剧烈增大,断层活化最为显著。     

硬厚岩层下逆断层采动应力演化与断层活化特征

上覆硬厚岩层受逆断层切割后,工作面顶板运动、采动应力会有异常变化。采用三维数值计算方法,模拟分析了上、下盘工作面向逆断层推进过程中的采动应力演化特征、煤层顶板运动特征及断层活化规律,并采用工程实例进行了分析验证。研究表明：在逆断层切割作用下,上盘工作面围岩呈倒楔形,采动应力向底板深处、顶板高处转移,围岩应力集中程度大于下盘工作面。下盘工作面与上盘工作面相比,采动应力受工作面与断层距离的影响较大。巨厚岩浆岩及其下部岩层形成类似“杠杆”结构,造成煤层顶板的下沉和反弹。逆断层下盘工作面煤层直接顶断层带活化的可能性大于上盘工作面,高位岩浆岩断层带活化的可能性小于下盘工作面。下盘工作面与逆断层距离40 m时断层开始活化;上盘工作面与逆断层距离40 m时,煤层直接顶断层带开始活化,与逆断层距离30 m时高位岩浆岩断层带开始活化。     

断层对采动应力的影响数值模拟研究

为研究断层对采动应力演化控制作用及发生滑移特征,利用FLAC3D软件对断层带两盘的接触状态以库仑剪切模型的接触面单元代替,模拟随着工作面沿断层倾向和沿断层走向推进时断层接触面上法向应力和剪切应力的演化特征、断层滑移危险性演化规律。结果表明:断层面上法向应力和剪切应力的演化具有明显的时空特征,且断层面上剪切应力对采动影响的敏感性强于法向应力;当工作面沿断层倾向或断层走向推进时,开采层上方断层先于开采层下方断层"活化",开采层上方附近断层在采空区距离断层20 m时最容易出现"活化",开采层下方断层在采空区距离断层小于10 m时滑移危险性最高;相比之下,工作面沿断层走向推进时开采扰动对开采层附近断层产生的影响较工作面沿断层倾向推进时大。     

超前支承压力对断层活化影响的数值分析

应用FLAC-3D对工作面前方的移动支承压力对断层活化的影响作用进行分析,研究结果表明:在断层上盘回采过程中,随工作面推进,断层周围的垂直应力和剪应力发生剧烈变化,在距离断层带45m时,断层已完全活化;支承压力对断层上下盘岩体位移量也产生显著影响,且断层上盘的应力和位移变化量明显大于断层下盘应力和位移的变化量。     

不同采高条件下正断层下盘开采支承应力演化与断层活化规律研究

以兴隆煤矿7302工作面工程地质条件为背景,采用连续介质数值模拟,研究了正断层下盘工作面推进过程中,采高对采动应力分布演化规律的影响以及断层活化特征,通过断层带法向应力与切向应力的比值作为判别依据,监测得到下盘工作面开采诱发断层活化规律。研究结果表明:下盘工作面向正断层推进过程中,断层的阻隔效应会造成采动应力的奇异性,不同采高条件对工作面超前支承应力演化规律影响显著;6m采高条件下,断层活化发生在工作面推进至距断层40m处。通过现场实例验证了不同采高条件下,工作面前方支承应力显现与断层的时空关系差异显著,现场实践中,需根据实际工程地质条件进行分析预测,提前布置工作面防冲措施,保证安全高效生产。     

不同倾角下正断层下盘开采支承应力演化规律研究

以正断层下盘工作面开采为背景,采用三维有限差分数值模拟软件FLAC~(3D) ,建立不同断层倾角下盘工作面向断层推进的数值模型。研究了工作面支承应力的分布特征和演化规律。研究表明:下盘工作面向正断层推进过程中,由于正断层切割了顶、底板岩层的连续性,采动应力的阻隔效应显著,断层倾角越小,其阻隔效应越显著。     

倾角对断层活化应力演化规律的计算机模拟研究

以某煤矿F2正断层的地质资料为依据,运用计算机数值模拟软件FLAC3D5.0对正断层在两盘工作面开采过程中断层带的应力变化、孔隙压力演化规律及围岩的孔隙压力进行研究,揭示了断层倾角对正断层的影响。研究结果表明:正断层在工作面开采之初断层带正应力变化不大,工作面开采至距断层35m位置时,断层带正应力快速增加,断层倾角越大,断层带正应力越大;不同断层倾角下,随工作面推进,断层带孔隙压力先缓慢增加,而后工作面距断层35m时,断层带孔隙压力迅速增加,工作面距断层相同距离时,倾角越大,断层带孔隙压力越大;正断层围岩的孔隙压力与断层倾角成正比,倾角越大,孔隙压力也越大。因此,在实际生产中需针对断层的性质,考虑断层倾角的影响,有根据地对断层保护煤柱进行留设,在保证安全的前提下,提高经济效益。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.     

Rare Earth Application in Steel in China

<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel     

Current situation and future trend of China rare earth luminescent materialindustry(continued)

<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why     

稀散金属产业的观察与思考

分析了近年来国内外稀散金属产业的生产、应用、资源与市场状况.铟锡氧化物靶材、砷化镓晶片、锗红外材料、铼高温合金和硒在电解锰及玻璃的应用等已成为稀散金属的主要应用领域.稀散金属的产量快速增长达到历史高位而导致了市场的失衡.以GaInP_2/GaAs/Ge,CIGS和CdTe为代表的非硅系太阳能电池是稀散金属的新兴应用领域,将给稀散金属带来日益增长的需求.